Synthesis of a cluster containing Eu(III) α2-P2W17O6110- and preliminary luminescence experiments

Abstract

We have prepared an unique cluster, [Eu(H 2 O) 3 (α 2 -P 2 W 17 O 61 )(Eu 2 (H 2 O) 7 )] 4 4– , 1 , in high yield and the preparation and crystallization is highly reproducible. This compound is based on the 1:1 [Eu (α 2 -P 2 W 17 O 61 )] 2 14– cluster where Eu2 is bound in the defect of the cap region of the α 2 -P 2 W 17 O 61 . Two other Eu(III) ions, Eu1 and Eu3 are each bound to two terminal oxygen atoms in that defect cap region. These two Eu(III) ions are bound through a bridging oxygen to other [Eu (α 2 -P 2 W 17 O 61 )] 2 14– clusters to form a network of [Eu (α 2 -P 2 W 17 O 61 )] 2 14– dimers, each connected by two aquated Eu(III) ions. Preliminary luminescence studies of a crystalline sample of 1 , suspended in methanol and reacted with organic ligands, show that the organic ligands indeed are capable of sensitizing the luminescence of the Eu(III). For comparison in solution, the organic soluble TBA 3 H[EuPW 11 O 39 ], 3 , was prepared and characterized. As shown from luminescence titrations and 31 P and 1 H NMR spectroscopy, this species reacts with phenanthroline and bipyridine, in acetonitrile, to form the 2:1 organic ligand: [Eu (PW 11 O 39 )] adduct. .